Basically, you might want to end your turn whenever you dont want a bad trigger or spell to happen, or if youd be penalized by an effect at the end of your turn
Sunken Citadel Land Cave This land enters tapped
6 Zinnia, Valley's Voice (#104) Borderless Raised Foil Zinnia, Valley's Voice is a Commander card that wants players to jam their deck full of creatures with powerful enters the battlefield abilities, so they can take advantage of offspring to trigger them twice
The indestructible counters are permanent, even if the saga enchantment creature itself leaves afterward
In the case of the former, you can even sacrifice Boromir in a key moment if you know that someone is holding free interaction that can stop someone else from winning the game
Cards even tend to have a significant increase to their price when they have names or types that are particularly difficult to reprint outside of a UB set